The problem with Heal is that it doesn't scale well once you get to the higher levels. It's designed to do healing based on a level 18 base HP bar, but that's not taking into consideration any items in the post-18 game. Plus it's countered by reduced healing effects like Ignite, Katarina's Death Lotus, Miss Fortune's Impure Shots, etc. While all heals are affected as such, in this case it's a tad more game breaking since it's eating up one of your summoner slots.
Revive is generally a poor choice due to the fact that it requires you to be dead in order to use it. Obviously you want to avoid being dead in the first place. While you generally can't avoid at least a handful of deaths in a game, you don't want to count on Revive being used as quick-back from death, compared to another skill which could have prevented that death in the first place.
That all being said, there are a few champions that can utilize these skills particularly well. A lot of support characters can utilize Heal quite well like Taric, Soraka, Sona, Alistar. Combining Heal with their built-in heal spells can provide an inordinate amount of burst healing which can be deceptive to the enemy team.
Revive is a good gimmick choice for a Twisted Fate or Pantheon playing mid to push the lane early. Once you're 6, go for a skirmish with your 1v1 opponent. If you win, great! But if you die, no big deal. Immediately revive, buy (be ready!) and ultimate back in, using your Gold Card (TF) / Shield Bash (Panth) to stun and finish them off. You have the speed boost from Revive so they wont escape, and now you have a good 15-20 seconds to push the tower. If you're well organized, you can have your jungler come help, or a sidelane move off to come finish the tower if you cant, keeping a strong 2v1 in another lane.
Additionally, Revive can be extremely strong late game when respawns are 50+ seconds long. You can turn a potential tower / inhibitor kill into nothing after a bad teamfight that's left you with few to no allies left. However, usually you don't want to ASSUME this is the fact, because you could have avoided that situation with a different summoner skill in the first place.
Basically, they're situational abilities with their place, but generally they're overshadowed by some of the more popular abilities.
Zileas, design director for LoL, explains:
The system guesses how good you are based on who you beat and who you lose to. It tries to make matches where it thinks you have a 50/50 chance of winning.
It knows pre-made teams are an advantage, so it gives you tougher opponents when you are in a pre-made team. We did fancy math to make the pre-made teams vs solo players matching fair. I even ran it by two math Ph.Ds and they said it made sense!
You can read the full shebang here. Basically, a custom ELO derivative is used to rank players and power the matchmaking system, so that you are paired with similarly ranked teams.
Best Answer
Many pros/high elo players adjust their masteries every game based on individual matchups in that game so that they get the most beneficial stats they can from masteries. For example, a mid laner may have a generic mid lane mastery page in which they take 2 points in Meditation (mana regen) and 3 points in Merciless (bonus damage to champions below 40% hp). This may be perfectly fine for someone like Ahri, but if you are instead playing Zed, it would be better to take the two points in Meditation and put them into Merciless, as Zed does not benefit from mana regen.
Also, in the case of marksmen, some marksmen do well with thunderlord's decree, while others like Jhin benefit more from Deathfire Touch. Also, if you are in a matchup against a heavy poke lane, it may be better to take Wardlord's Bloodlust to avoid being pushed out of lane as easily.
TL:DR It is fine to have premade mastery pages to save time when setting them up, but if you want to optimize you stats gained from them, you should always try and fine tune them each match based on the champions you are facing.