Purport

This Shloka is in continuity from earlier Shloka started with 9.29 where Shri Krishna declared, “I regard all living beings with equality.”(9.29)
Not only humans, but every living being is equal to Bhagvan Shri Krishna. And then in the next 2 Shlokas, Bhagvan Shri Krishna described even a sinful person has the right to acquire the same state of as acquired by a noble person if he corrects his mistakes and takes refuge into Shri Krishna’s devotion.

Continuing on the same subject, Bhagvan Shri Krishna in this Shloka described that his doors are open for everybody. But what makeable in Shloka is that it has mentioned different sections of society. Though mentioned sections have nothing in common as per the social structure is concerned, except one thing that each of these sections has fewer opportunities to access scriptures or spiritual masters.
The first section mentioned is people unfortunately born in a sinful family, having somebody with criminal or negative backgrounds. Such people having no fault of their own face a lot of difficulties in society. They carry the burden of their negative background. That affects both their thought process and confidence. Secondly, since they have a negative family, they might be driven in a negative direction by the family environment. Spiritual development is very difficult for such people. Bhagvan Shri Krishna says that such people if simply take refuge in Him(Shri Krishna) get the benefits of higher spiritual work done by other resourceful.

Other sections motioned are women, vaishya and Shudras. As we all know women always have added responsibilities of family and find it difficult to dedicate time to spiritual practice.
Vaishya is the middle level of society most of the time extremely busy in the profession, business or agricultural work. They too find it very difficult to dedicate time for spiritual development.

The last section listed Shudras. They are the people who are not having much skill and most involved in physical work. It is very difficult for them to spend time on spiritual practice.

Bhagvan Shri Krishna hence specified that it's not about learning scripture and spending time on spiritual development, but about the true intentions.

A person might be very busy or unskilful for spiritual practices, but if he has the true intentions and takes refuge in Shri Krishna with honesty attains the supreme state of Moksha which is otherwise attained by the hard practice of Yoga, Tapasya or Sannyasa.

This is to be noted that this shloka is one of those Shlokas which are highly misquoted by some people. Therefore it is very important to read this Shloka carefully along with all Shlokas from #29 to 34. Then only the context and subject become clear.