Islam says our parents have the right to be respected. What if they don't deserve it? Does "respect" in this context mean that we should not disrespect them or does it mean that we must respect them?
A few points that I hope will help inshaAllah:
① Allah (ﷻ) said do both.
- Do not disrespect: "..say not to them [so much as], "uff," and do not repel them.." (Qu'an 17:23)
- Respect them: "..speak to them a noble word; And lower to them the wing of humility out of mercy and say, "My Lord, have mercy upon them as they brought me up [when I was] small." (Qur'an 17:23-24)
And remember, Allah (ﷻ) said to do the above despite knowing not all parents are perfect.
② The above command of respecting parents stands even if you think they don't deserve it (and Allah (ﷻ) knows best who deserves what). For example, as much as Allah (ﷻ) says shirk is the worst sin, he still told the Believers to bear the company of their parents with kindness/justice even if their parents called them to it. The same applies with sins lesser than shirk!
Qur'an 31:15: But if they endeavor to make you associate with Me that of which you have no knowledge, do not obey them but accompany them in [this] world with appropriate kindness and follow the way of those who turn back to Me [in repentance]. Then to Me will be your return, and I will inform you about what you used to do.
So regardless of your current situation, remember that your mother bore you for months and months in hardship as Allah (ﷻ) pointed out in the Qur'an. Thereafter your parents raised you while you were helpless on your own as the verse above pointed out. You cannot forget these great acts of kindness due to their 'not so great' moments.
③ If you think they don't deserve respect, do you think you deserve Paradise? We can never get into Jannah on virtue of our own actions but the least we can do is overcome our Nafs (inner self) and do the superior deeds.. as hard as it may be. To treat 'rough' family members with kindness is the superior path, and is as if you are throwing hot ashes upon their face, as per the example of the Prophet (ﷺ).
Sahih Muslim 2558: Abu Huraira reported that a person said: Allah's Messenger, I have relatives with whom I try, to have close relationship, but they sever (this relation). I treat them well, but they treat me ill. I am sweet to them but they are harsh towards me. Upon this he (the Holy Prophet) said: If it is so as you say, then you in fact throw hot ashes (upon their faces) and there would always remain with you on behalf of Allah (an Angel to support you) who would keep you dominant over them so long as you adhere to this (path of righteousness).