Plural Forms – Is ‘Videos’ Correct as the Plural of ‘Video’?

As pointed out in your question software is a mass noun also known as uncountable. Some uncountable nouns can be used in plural, and Google n-grams reports a number of instances for softwares:

"These softwares permit simple mapping of the existing data and offer good compatibility with other softwares." (Don De Savigny, ‎Pandu Wijeyaratne - 1995)

"In addition, these softwares, although said to be "symbolic" fail to provide explicit motion equations of the considered system." (Thomas Lee - 1993)

"Many microcomputers are equipped with softwares built on ROM." (The Malaysian Agricultural Digest - Volumes 2-3 - Page 48)

"All ten softwares have been written in Turbo Pascal for the IBM and IBM compatible computers." (Mark Keegan - 1995)

"the communication between the two softwares uses a common memory zone." (Philippe Geril - 1986)

"Dozens of well-developed softwares for computer-assisted molecular design based on 3D—CG are commercially available and are now widely used (8)." (H. Timmerman, ‎T. Fujita - 1995)

"The Decision Making Software is a set of softwares to make control decisions of the agent." (M Ahmad, ‎William G. Sullivan - 1993)

"There are many commercial data mining softwares available in the market that can be applied to financial applications." (George T. Albanis - 2003)

The question arises whether this use of softwares is the result of the influence from non-native speakers of English or simply the natural evolution of its use. This is a question especially difficult to answer for technical terms such as software.

It is because you are not counting the thousands, you are counting the trees.
So when you say:

There are seven thousand trees.

The noun trees is countable and plural. thousand is an adjective in this example. Even if you don't say "trees" its still implied.

But you could say:

There are thousands and thousands of trees."

where "thousand" is used as a noun and you are counting groups of 1,000.