As long as the company (management) is pushing strongly for pushing new releases fast, then there is no solution to your problem. You can ask for a "day of zen" where all the programmers go off-site and discuss "what is good code" until everyone is fired up, only to return to work and get back into the old mode. The todo list and release dates hasn't changed.
In terms of "good code" there is of course never any excuse not to have properly written, formatted, and commented code etc. I am assuming the main problem with your code is it is somehow poorly architected and quality checked; bad or inconsistent design, commit stuff as soon as things seem to work, avoid spending time on writing tests - that sort of thing. New stuff gets layered on top or some quick band aid is applied, and it eventually turns into a big mess.
For that kind of code problem, "fixing the problem" is a big thing. It is in itself an investment - the poor development processes has incurred a development "debt", which requires man-hours to fix. Lots of stuff may have to be rewritten. And in return for all this time, product managers are getting no new features to show the customers - "only" a more stable product. Secondly, new stuff will (in the short term) take a little longer to implement, because doing it right takes a little longer, plus various problems with the old code will surface that need to get fixed. Thirdly, the team's mentality towards what it means to write a good product needs to be changed - and some of the team members may not be able to change their attitude, or may not have the skills to write and architect proper code.
In the end, this is a problem that needs to be discussed with the powers in charge, as a big and serious issue. While it may be comforting for management to let things just run as they are, this is the type of approach that leads to complex and unmaintainable products. Which at some point, so much debt has been incurred that product is completely unstable, everyone is caught up in "fixing" bugs and crashes, and new features take forever to fix even when trying to take the quick route.
Unfortunately, with the typical near-sighted "next quarter" focus, it is an uphill battle you may well end up losing.