You're trying to invent your own definition for a term you clearly know nothing about.

Here's your dictionary reference to help you understand what a monopoly is:

http://dictionary.reference.com/browse/monopoly

mo·nop·o·ly   [muh-nop-uh-lee]  Show IPA

noun, plural mo·nop·o·lies.1.exclusive control of a commodity or service in a particular market, or a control that makes possiblethe manipulation of prices. Compare duopoly, oligopoly.

2.an exclusive privilege to carry on a business, traffic, or service, granted by a government.

3.the exclusive possession or control of something.

4.something that is the subject of such control, as a commodity or service.

5.a company or group that has such control.

Adobe fits none of those definitions. They are a company that designs software and buys out other software when its failing, or when its owners want to sell. There is nothing illegal or wrong about doing that in a free market. 

Adobe does not prevent anyone else from developing their own software. If they did, as I stated before, then there would be no other options BUT Adobe software. 

If you don't like their business practices you're free to not use them, find someone else's software to use. If they were a monopoly then you wouldn't have that freedom. You'd either use their software or none at all. Their customers and clients are the reason they currently dominate the market. Dominating the market is not being a monopoly, it's just being a business that has made the right decisions to get them where they're currently at. 

~Shane