Adobe didn't strong-arm anyone into selling. They're not a monopoly because they aren't preventing anyone from building their own software package and putting it up for sale as a true competitor to Adobe's line of software. The companies who sold out to Adobe are just as responsible for putting Adobe in the position of power that Adobe is currently in. 

If they were a true monopoly then Gimp would not exist, Paint Shop Pro would not exist, and anything any other software company tried producing that was similar to Adobe's software would not exist. 

Try learning what a real monopoly is before you go throwing the term around. 

There is no need for government intervention. That only leads to tyrany. Anyone is free to design whatever software they want, they just need the right team with the know-how to build a package that is viable enough to rival Adobe and make Adobe's customers move to them. That is the nature of the free market and capitalism. So far no one has bothered to put the resources into doing so. That's not Adobe's fault. 

 

~Shane