Problem of hop on hop off projects

Hop on hop off projects is the term I made. This means you join a project in short term, then join other project in short term, like hop on hop off tour buses. (I just don't know any word describes such a style of driving project, drifting?)

I'm currently working with kind of scrum environment. Why kinda? It's because sprint period is rather longer than usual (4-5 weeks) and no standup meeting. The same part is that each sprint I get new task(s). By now, the tasks I've got assigned were not really related so each time I need to look into something I don't know (of course product specific thing). Thus hop on hop off projects.

It might be only me but if I don't have long term commitment of a project, then I lose interest and start writing crappy code. This is because I start thinking that "I would move to next something I don't know anyway why should I write maintanable code?". Probably, I don't feel any responsibility to the code I'll never see in future. (Plus, the current code base is really pile of shit, I don't want to swin into that. Too risky...)

What happen if I'm such a state? For example:

• Start using copy&paste instead of extracting common use-case somewhere usable place.
• Using magic number/string as everybody is doing.
• No tests (well, I don't think there's a culture writing a test in this company...)

These are happening right now. Of cource I know I'm not doing right but risk is too high if I touch/refactor something without tests. I do what I suppose to do but I'm not those highly motivated people so I don't much care as long as I don't see it anymore.

The funny thing about this is that my company is actually developing one product however they don't assign to the same project (so far) or don't have long term assignment. Each task must be done at most a month. I understand that's the basic idea of scrum. But by now, I can only see the greate failure, such as:

• Wrongly abstracted classes
• No tests
• Copy&pasted code
• Only few people know the structure of code/architecture
• No refactoring (of cource, there's no efficient tests!)
• etc.

I'm such a lazy person so I'd write as maintanable as possible if I need to maintain the code. But if I don't have to, this laziness seems to take into horribly.
Or maybe I'm considered as one of useless developers so they don't want me to do anything but piling crap. That's fine by me, as long as they pay my salary.