As far as I know diversification is for everybody, unless you are not a human being. As a new investor having another source of income aside from your Bitcoin investment is exactly what would going to help you hold for future. Because you can't just rely on one thing, as long as you are planning to invest in Bitcoin is also very important to have something that would be fetching you money so that Incase if any emergencies arise you would be able handle it without touching your Bitcoin investment.
Yes it is true that diversification is suitable for everyone, but more precisely, it is suitable for those with middle to upper financial levels because success depends on the capital invested. Of course, diversifying assets is much better to cover the failure of one investment. As the saying goes, don't put your eggs in one basket, but for those with limited income, it is more efficient to concentrate on one asset with solid fundamentals rather than dividing it into 5 places and getting nothing. Sometimes one investment can also be very valuable if you really get the right asset.