I suspect that many of those investors just want out of the housing market and will invest in different segments. 

Each tenant segment has different behavioral characteristics.

There is a reason he will only tell you the general market segments he is in and not the specific funds, the advice is supposed to be shrouded in enough mystery that you don't feel confident doing it on your own. 

Not only is it free but the information in each segment is so valuable.

Is it a moving target defined by the mood of a segment of society at a given time, or is there something more fundamental and unchanging that we should measure it by?   

Tenants who don’t pay their rent still regard, as does a whole segment of society, landlords as greedy evil for evicting the non paying tenants.  

So 2-3 single families isn't too big of a value but if you were adding a 50 unit I would have some concerns about not having the assets a little more segmented.

In our investment property, we actually looked for single family homes with large fenced back yards to cater to this segment as it was so difficult to find when we needed it, and we only charge a higher refundable security deposit, no pet fee and no pet rent.  

That noob FTHB segment of my practice has grown really fast since I made the banker -> broker switch (which is why I did it), but my landlord loan production didn't really change all that much (I didn't expect it to), it went up MAYBE 10% or so, and that's mostly concentrated among those that say "I'm a real estate investor!"

The best investors go against the grain and invent the market segment they occupy.