So you can buy this software for 24.99, and then after a month of use, decide not to use it - cancel your subscription - and the software then becomes useless to you. You've just lost 24.99 and end up with nothing to show for it.
If you buy this software for 299.00, you can use it for a month and then decide its not for you - you've lost 299, but you've still got the software on your system, and can change your mind 3 months later, if you need to, and still have a valid, working tool.
I dunno, I just don't like the idea of having to be beholden to a company, every month, for the right to use a developer tool that I'd be happier having a permanent installation of .. it reeks of the trappings of a walled garden, and even if the bells and whistles are worth the hassle, the politics of the situation just rubs me up the wrong way.
I'd be much happier buying a tool I'm going to use, at my own discretion either regularly, irregularly, or not at all (my choice), than have to ask permission to use it every month. Its the asking-of-permission, expressed as a subscription model, which is the core of my disinterest.
(I've signed up for a 14-day trial, anyway, because the tool interests me enough to warrant further investigation, but unless I find some serious bells and whistles, I'm quite sure I'll be throwing it away after the trial..)